The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
In order to perform an application of a cosmetic product making skin care of a patient as well as a massage of this skin, a known application head, shown in particular by the document WO-A1-2011067500, includes an elongate body having at its front end a spherical-shaped housing fittingly accommodating a massage ball of the skin.
The spherical housing has an outer diameter slightly lower than that of the ball, so as to leave a large surface of this ball outside the housing, which can come into contact with the skin by rolling thereon.
The application ball is retained at the bottom of its housing by a magnet which is held in the body slightly rearward of this housing, in order to permanently exert an attraction on the ball comprising a material attracted by this magnet.
The care product contained in the body, such as a cream or a gel, can exit through the bores located in the surface of the spherical housing in order to come into contact with the rear portion of the ball, then to spread on the skin during massage thereof by rolling this ball which drives and distributes the product.
In order to facilitate a passage of the care product between the surface of the spherical housing and the ball, this housing includes small inner bosses which keep some spacing between the ball and this surface, allowing an exit of the product through the bores of this surface.
A problem which arises with this type of application head is that the passage allowing the exit of the product is never closed, even by pressing on the ball during massages of the skin, the bosses permanently keeping the spacing which allows this passage. It is therefore possible, during use, to have an involuntary product exit which applies a very significant amount.
Furthermore, the device is still open, the product contained in the reservoir cannot be preserved in good conditions, its volatile components may evaporate, while other components can be oxidized or contaminated by external agents.
The document of the prior art also has alternatively an application head type having small bearing balls held in cavities made in the spherical housing, which can slightly slide axially to pass to the inside this housing by forming inner bosses.
The bearing balls are retained backwards by magnets disposed in the body, which attract them, and which also attract the application ball. Thus, a possible slight axial movement of the application ball, which can, by following the bearing balls, move away from the spherical surface in order to allow a passage of the care product, or tighten over this surface in order to close this passage, is obtained.
However, this type of application head containing bearing balls held by a magnet, is relatively complex to be performed, and includes a high cost. Furthermore, the product coming from the reservoir can seep into the housings of the bearing balls, generating a discomfort to the operation, an oxidation of the metal portions, or a proliferation of bacteria.